Fasting is the "easy" part where everything is all worked out for you. Now comes the real part requiering education, focus and dedication or you'll gain >all< the weight back really quick and possibly put on more than you lost. It is going to take educating yourself and a no if and or buts about it lifestyle change and regular exercise. Specifically more so after a long fast since ALL forms of fasting will slow the metabolism down and exercise is the best and most efficient way to bring it back up. It could take 6 to 8 weeks to bring the metabolism back online and possibly more since most overweight folks metabolisms are already slow to begin with.